The European ship fleet counts 23,000 vessels, accounting for the 40% of the global gross tonnage. The marine industry is a major prosperity engine of the EU contributing a total of €147bn to the GDP and supporting more than 1.7m jobs. Non-Destructive Testing (NDT) inspections are the common tools adopted to assess the vessels’ structural integrity throughout the vessel’s lifetime. But such technology is not without challenges. During new building construction, for instance, ship hull weld inspection is a challenging process as safety-critical welding length exceeds 120m in large vessels and requires the involvement of inspectors on site using scaffolding or cherry-pickers. These procedures are time-consuming and incurring loss of revenue with costs amounting to more than €150k per inspection. To some extent the use of the inherently dangerous radiographic techniques, , with the associated health and safety issues, is phased out in Shipyards. These challenges give rise to a unique opportunity to redefine ship NDT inspection by utilizing, a laser-guided robotic crawler able to automatically track the weld and inspect the hull while the ship is at sea. Through a combination of bleeding-edge ultrasonic and electromagnetic techniques ShipTest aims to accurately inspect welding of metal plates and corrosion, allowing for permanent digital inspection records to be produced while eliminating the need for inspection using scaffolding or cherry pickers and the dangers associated with industrial radiography.
This paper will describe the ShipTest system and the utilization of the technologies employed; Phased Array Ultrasonic Testing (PAUT), Alternating Current Field Measurement (ACFM) and laser profiling of the welded joint, to carry out the inspection of welded joints on ship hulls using a robot to drive the sensors, a laser guidance system to follow the welded joint and the software developed for the data capture and display of this technology.